The present invention relates to a method of manufacturing a semiconductor device and the semiconductor device. Specifically, the invention can be preferably applied to a semiconductor device using a nitride semiconductor.
GaN-based nitride semiconductor is expected to be applied to transistors for high withstand voltage, high output, and high frequency purposes due to its wide bandgap and high electron mobility compared with Si and GaAs, and has been actively developed in recent years. Among such transistors, a transistor having normally-off characteristics is particularly useful, and thus a structure of a transistor has been investigated to allow the transistor to have the normally-off characteristics.
For example, International Publication WO 2110/064706 discloses a MIS field effect transistor using a group III nitride semiconductor layer, which is turned on at a practical positive gate voltage and can operate at high speed.